Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 242022
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
322 PM CDT TUE MAR 24 2015

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT TUE MAR 24 2015

SEVERAL FACTS WILL INFLUENCE SNOWFALL AMTS AND WHETHER ANY SLEET
FALLS DURING THE EVENING MAKING FOR MORE TRAVEL PROBLEMS.

INITIAL DRY ATMOSPHERE ACROSS THE WESTERN GREAT LAKES AND THE
PREVAILING EAST/SE WIND AS KEPT THE PRECIPITATION FURTHER TO THE
SW OF OUR CWA THEN WAS PREVIOUSLY FORECAST. IN
ADDITION...THUNDERSTORMS ACROSS THE IA/MO BORDER EARLIER AND THE
SFC LOW ACROSS KANSAS HAS KEPT OUR REGION FROM HAVING THE OPTIMAL
MOISTURE ADVECTION FROM THE LOWEST 10K. ALTHOUGH WE DO HAVE
MOISTURE IN THE LOWEST 2K WHICH KEPT TEMPS FOR RISING TOO MUCH
ACROSS WESTERN MN IN CLDS/FOG TODAY.

THE BEST SCENARIO AND FORECAST FOR TONIGHT IS TO KEEP HIGHEST POPS
AND ASSOCIATED SNOWFALL AMTS IN FAR SC/EC/SE MN AND INTO PORTIONS
OF WC WI. EARLIER TODAY I DID CHG THE ONSET OF THE WINTER WEATHER
ADVISORY BASED ON THE DRIER AIR AND PRECIPITATION DISSIPATING THIS
AFTN.

SEVERAL OF THE LOCAL SHORT TERM MODELS HAVE TRENDED FOR THE GREATEST
POTENTIAL OF 2+ INCHES OF SNOW IN SC/SE MN AND WC WI...SOUTH OF
RIVER FALLS AND MENOMONIE WISCONSIN. THIS IS ALSO WHERE THE
CURRENT WINTER WEATHER ADVISORY IS IN EFFECT. CURRENT CONVECTION
IN SOUTHERN IA AND A SFC LOW IN EASTERN KANSAS WILL ALSO PLAY AN
IMPORTANT ROLE TONIGHT AS THE CIRCULATION AROUND THIS LOW DRAWS IN
DRIER AIR FROM THE WESTERN GREAT LAKES LATE THIS AFTN/EARLY
EVENING. ACROSS THE EASTERN DAKOTAS...THE SFC FRONT WILL KEEP A
SMALL AREA OF -RA/-SN IN WC/CENTRAL MN THIS EVENING. BUT THIS AREA
WILL BE MORE DISORGANIZED BASED ON THE SEPARATION OF THE TWO
WEATHER SYSTEMS MOVING ACROSS THE CONUS. IN ADDITION...SLEET
PROBABILITIES ARE LOW DUE TO THE NATURE OF THE STRONGER FORCING
SOUTH OF OUR CWA...WITH ONLY A SMALL AREA NEAR THE IA/MN BORDER
WHERE LOCAL CAMS HAVE SOME HIGHER REFLECTIVITY WHICH IS INDICATIVE
OF SLEET/OR +SN IF CONDS WARRANT. WILL KEEP LOCAL SNOWFALL AMTS
AROUND 2-4 INCHES FROM KAEL TO KEAU. ELSEWHERE...AMTS WILL BE LESS
THAN ONE INCH.

SPECIFICALLY...AN AREA OF -RA/-SN IN NW IA WILL CHG TO -SN AS IT
MOVES FROM SW TO NE ACROSS MN AND INTO WC WI OVERNIGHT. AS THE
SFC FRONT MOVES INTO WESTERN MN...ANY LEFT OVER PRECIPITATION
SHOULD END AS THE MAIN AREA OF PRECIPITATION PIVOTS TO THE N/NE
ACROSS NORTHERN MN TOWARD MORNING. WILL CONTINUE THE LOW CHC/S OF
-RA/-SN IN CENTRAL MN AND WC WI BASED ON THE CIRCULATION ACROSS
THE DEPARTING UPPER LOW IN SOUTH CENTRAL CANADA.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 CDT TUE MAR 24 2015

THE LONG TERM FORECAST PERIOD INCLUDES VERY LIGHT PRECIPITATION
AMOUNTS IN THE FORECAST AND STARTING OFF WITH BELOW NORMAL
TEMPERATURES BUT WARMING INTO NEXT WEEK.

THE SYSTEM EXPECTED TO IMPACT SOUTHERN MN AND WESTERN WI TONIGHT
THROUGH TOMORROW...WILL ADVANCE NORTHEAST AND EVENTUALLY MERGE WITH
ANOTHER DISTINCT WAVE/PIECE OF ENERGY THAT IS CURRENTLY MOVING
THROUGH WESTERN NORTH DAKOTA. THIS MERGER WILL TAKE PLACE TOMORROW
AFTERNOON INTO THE EVENING AND IS THE FIRST FOCUS OF THE LONG TERM
PERIOD.  WE HAD BEEN CARRYING SOME LOWER POPS ACROSS CENTRAL MN
THROUGH NORTHWEST WISCONSIN...BUT DETERMINISTIC MODELS SUGGEST LOW
LEVEL DRYING WILL PUSH THE BEST CHANCE OF ANY MEASURABLE
PRECIPITATION NORTH OF OUR FORECAST AREA. SO...PULLED MOST OF THE
POPS AFTER 00Z THURSDAY AND INSTEAD INSERTED FLURRIES/SPRINKLES
ALIGNED WITH THE SURFACE TEMPERATURES FROM MILLE LACS LAKE THROUGH
LADYSMITH.

FOR THURSDAY AND FRIDAY...A SURFACE HIGH WILL DROP SOUTH OUT OF
CANADA AND MOVE DIRECTLY OVERHEAD BY MID DAY FRIDAY. THE CORE OF THE
COLDEST AIR ALOFT WILL MOVE DIRECTLY OVER THE GREAT LAKES SO WE WILL
BE TO THE WEST OF THE COLDEST TEMPERATURES...BUT 850MB TEMPS ARE
STILL EXPECTED TO DROP INTO THE -10C TO -18C RANGE.  WITH THE CLEAR
SKIES AND LIGHT WINDS...EXPECTING SURFACE TEMPERATURES TO FALL INTO
THE TEENS BY FRIDAY MORNING.

SATURDAY WILL BEGIN TO MODERATE AS SOUTHWESTERLY WINDS SETUP AS THE
HIGH MOVES EAST OF US.  A FAIRLY STRONG IS EXPECTED TO MOVE EAST
FROM MANITOBA THROUGH ONTARIO...WITH A TRAILING COOL FRONT EXTENDING
SOUTHWEST OF THE LOW.  THIS FRONT WILL SWEEP THROUGH OUR AREA ON
SUNDAY MORNING...AND THE POPS IN THE FORECAST SATURDAY NIGHT ACCOUNT
FOR LIFT AHEAD OF THE BOUNDARY. TEMPERATURES ACTUALLY WONT DROP MUCH
AT ALL HOWEVER AS THE WESTERN RIDGE WILL QUICKLY PUSH IN BEHIND IT.
SIGNS STILL POINT TO A WARMING TREND FOR EARLY NEXT WEEK WITH THE
WESTERN RIDGE CONTINUING TO PUSH EAST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1240 PM CDT TUE MAR 24 2015

MAIN CHGS THIS AFTN WAS TO HOLD OFF ON SIGNIFICANT PRECIPITATION
UNTIL AFT 00Z. SLOWER MOVEMENT OF PRECIPITATION ACROSS NE/SD/IA
HAS LED TO A SLOWER SOLUTION ON THE ONSET OF -RA -SN AND OTHER
MIXED PRECIPITATION. IN ADDITION...HIGHER PRECIPITATION
RATES...ESPECIALLY IN TERMS OF SNOWFALL HAVE SHIFTED SLIGHTLY TO
THE SE OF OUR CWA. THEREFORE VSBYS MAY NOT BE AS LOW AS PREVIOUSLY
EXPECTED AT RNH/STC. OTHERWISE..KEPT -RASN DURING THE ONSET...WITH
A CHANGE OVER TO ALL SNOW DURING THE MID/LATE EVENING. CIGS WILL
LIKELY HOLD IN THE IFR/MVFR RANGE THRU THE PERIOD...WITH ONLY
RNH/EAU HAVING VFR INITIALLY THIS AFTN. WINDS WILL REMAIN FROM THE
SSE AND GUSTY THIS AFTN...BECOME MORE S/SW OVERNIGHT AND VEER TO
THE W/NW WEDNESDAY MORNING. HIGH CONFIDENCE IN MVFR/IFR CIGS
CONTINUING THRU 00Z...WITH LOWER CONFIDENCE ON VSBY RESTRICTION
THIS EVENING IN SNOW.

KMSP...

MAIN CHG FOR THIS TAF PERIOD IS TO HOLD OFF ON PRECIPITATION UNTIL
AFT 2Z...WITH THE BULK OF THE RAIN...CHG TO SNOW AFT 3Z. BEST CHC
OF IFR VSBY/CIGS IN SNOW WILL OCCUR IN THE 3-6Z TIME FRAME. WINDS
WILL BE GUSTY FROM THE SSE THIS AFTN...WITH WINDS DECREASING THIS
EVENING...VEERING TO THE SW BY 12Z...THEN MORE WNW/NW BY 18Z AND
BECOMING GUSTY AGAIN.

/OUTLOOK FOR KMSP/

WED NIGHT...VFR. WINDS NW 15G25 KTS EARLY.
THU...MVFR POSSIBLE EARLY. WINDS NNW 15G25 KTS.
FRI...VFR. WINDS NW 5-10 KTS BCMG SW IN THE AFTN.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 AM CDT
     WEDNESDAY FOR MNZ077-078.

     WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 4 AM CDT
     WEDNESDAY FOR MNZ082>085-091>093.

WI...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 AM CDT
     WEDNESDAY FOR WIZ024>028.

&&

$$

SHORT TERM...JLT
LONG TERM...SPD
AVIATION...JLT


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